Winding arrangement for an electric machine

ABSTRACT

The invention relates to a winding arrangement for an electric machine with a polyphase winding, in which a plurality of coils or coil groups connected in parallel ( 50, 52, 54, 56 ) are connected with a conductor rail ( 40, 42, 44, 46 ). This makes it possible to connect the coil ends directly and without connecting pieces with the electric power supply. The conductor rails ( 40, 42, 44, 46 ) are preferably arranged at one or both face sides of the post of the electric machine below the slot openings, i.e., in the area of the back of the post. 
     Furthermore, the invention is aimed at an corresponding manufacturing method for a winding arrangement of a polyphase winding for an electric machine, in which the coils or coil groups connected in parallel ( 50, 52, 54, 56 ) of the winding are connected with one of the conductor rails ( 40, 42, 44, 46 ).

CROSS-REFERENCE TO OTHER APPLICATIONS

This Application is a National Phase of International Application No.PCT/EP02/01647 filed on Feb. 15, 2002, which claims priority from GermanPatent Application No. 101 11 509.1 filed on Mar. 9, 2001 and GermanPatent Application No. 101 16 831.4 filed on Apr. 4, 2001.

FIELD OF THE INVENTION

The invention generally concerns windings for electric machines, and, byway of example, a winding arrangement for the stator of an electricmachine with a polyphase winding with several phase branches.

BACKGROUND OF THE INVENTION

Electric machines (e.g. asynchronous or synchronous machines with arotary or linear embodiment, in which “electric machines” refer both toengines and generators) are generally equipped with a winding. Thecurrent flowing through the machine generates a moving magnetic fieldcausing the armature to move over the air gap between the stator and thearmature. The winding is generally incorporated in the slots of a statoror rail armature, and usually runs parallel to or in a small angle withthe rotational axis in the case of a radial field machine.

The number of phases of the winding of a polyphase alternating currentmachine generally corresponds with the number of branches, which usuallycover several coils with one or more windings. Each coil generally lieswith both so-called “coil sides” in the slots, whereas the so-called endwindings connect the sections of the winding arranged at the face sidesof the stator. The coils or serial connections of several coils (coilgroups) of a branch are generally connected on one end with a powersupply. On the other end, the branches are joined, for example, at theso-called neutral point. Alternatively, the branches could also be deltaconnected.

A branch often comprises several coils or coil groups placed in parallelin the slots at regular intervals along the perimeter of the stator orconductor rail, in which the ends of the coil connected with the powersupply (e.g., with the three phases of a source of alternate current aregenerally also placed at regular intervals along the perimeter of thestator or conductor rail. The coil ends then generally have with longerconductor sections, which are pulled forward from the coil ends to acentral connection area and connected with said connection area. Eachconductor can have several connecting points, whereby the coil end wouldagain be connected with the power supply by means of a longer connectingpiece.

SUMMARY OF THE INVENTION

The invention relates to a winding arrangement for a stator of anelectric machine with polyphase winding with multiple phase branches.The winding arrangement comprises coils or coil groups and conductorrails with at least one terminal. Each phase branch comprises aplurality of coils or coil groups connected in parallel. The conductorrails are located at least partly around the stator. At least one end ofthe coils or coil groups connected in parallel is connected with one ofone of the conductor rails in such a way that said conductor rail formsa current conductor connecting the terminal with the parallel-connectedcoils or coil groups of a phased branch.

Other features are inherent in the disclosed products and methods orwill become apparent to those skilled in the art from the followingdetailed description of embodiments and its accompanying drawings.

DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described, by way of example, andwith reference to the accompanying drawings, in which:

FIG. 1 is an exploded view of a first embodiment of a conductor railunit;

FIG. 2 is an exploded view of the conductor rail viewed from the frontof FIG. 1;

FIG. 3 is an exploded view of another embodiment of the conductor railunit of the invention;

FIG. 4 is a diagrammatic view of a joint of a conductor rail;

FIG. 5 is an exploded view of another embodiment of a conductor railunit;

FIG. 6 is a diagrammatic top view of a conductor rail;

FIG. 7 is an exploded view of an embodiment of a conductor railcomprising different ring sectors;

FIG. 8 a is a perspective view of a first type of L-shaped structuralpart;

FIG. 8 b shows Cross-sections along the A—A and B—B lines of FIG. 1;

FIG. 9 is an exploded view of a second type of L-shaped structural part;

FIG. 10 is an exploded view of yet another type of L-shaped structuralpart;

FIG. 11 is an exploded view of yet another type of U-shaped structuralpart;

FIG. 12 is an exploded view of an arrangement comprising severalL-shaped structural parts;

FIG. 13 shows the same view as FIG. 12, however, with an additionalL-shaped structural part;

FIG. 14 shows the same view as FIG. 13, with yet another L-shapedstructural part;

FIG. 15 is an exploded view of a section of a stator or armature of anelectric machine with slots comprising L-shaped structural parts;

FIG. 16 is a diagrammatic top view of the slots of the body of a statoror armature provided with U-shaped structural parts;

FIG. 17 is a diagrammatic view of the face side of a spooled body of astator;

FIG. 18 is a winding diagram of a three-phase winding of a firstembodiment;

FIG. 19 is a winding diagram of a three-phase winding of a secondembodiment;

FIG. 20 is an exploded view of a section of a stator completely providedwith a winding and a conductor rail set.

Those parts in the drawings with the same or similar functions are inpart marked with the same reference signs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following clarification of the preferred embodiments with anarrangement of stator windings has been added for the purpose ofsimplification; this equally applies to the corresponding armaturewindings, in which the conductor rails also serve as collector rings, ifnecessary. FIGS. 15 and 16, for example, show equal views of a stator(in the case of FIG. 15, it is an interior armature machine) and anarmature (in the case of FIG. 16, it is an exterior armature machine).

FIG. 1 shows a first embodiment of a conductor rail unit. Beforeclarifying this figure, here are some remarks concerning the preferredembodiments.

The preferred embodiments apply to the arrangement of windings for thestator of a radial field machine with an interior armature. Therefore,the lateral direction of the slot has been laid out as the axialdirection, and the direction of the depth of the slot as the radialdirection. However, the windings and conductor rails described can alsobe used for exterior armature machines. An axial field machine can alsobe equipped with a suitable conductor rail. The same applies to linearmachines, in which the conductor rails rotate around the (leveled)stator.

The stator shown in the figures comprises a stator body in the form of astack of slotted sheet metal in order to incorporate the winding slotbars guiding the magnetic flow. The non-slotted part creates theso-called backside. The “faces” refer to the sides of the stator bodywhere the slots are cut crosswise. For the radial field machines shown,these are the axial foreparts of the stator body.

In the described embodiments of the arrangement and the manufacturingmethod for a winding arrangement of a multiphase winding, the winding isconnected with a power source by means of rotating conductor railscomprising several coils or coil groups placed in parallel. They arefavorably connected at regular intervals along the perimeter of theconductor rail, as prescribed by the winding diagram. This means thatthe coil ends are not connected with connecting pieces with centralconnecting points, but can be directly connected, e.g. by welding, undercertain circumstances with the conductor rails. Therefore, the use ofrotating conductor rails is also favorable in case of two differentcurrent paths between the power source and the coil end in each case. Ifthe electric connection would be interrupted somewhere along theconductor, all coils or coil groups would still receive power from thesecond redundant current path.

The number of conductor rails used for the power supply of the describedpolyphase windings generally corresponds with the number of phasesand—in the case of a star connection—a conductor rail for the starpoint, i.e., the connection of the phase conductors of the winding. Theconductor rail for the star point is not needed for delta connectedphases.

Following a preferred embodiment, the electric machine comprises astator with slots, in which the conductor rails are arranged on one orboth face sides of the stator in the direction of the depth of the slotbelow the slot openings. In other words, the conductor rails are locatedat the face side of the back of the stator, which secures the return ofthe magnetic current. Indeed, in the preferred embodiments of thewinding, the winding heads are arranged in such a space-saving way thatthey do not require additional radial space at the face sides thanprovided by the depth of the slot. Consequently, the space at the backend of the stator is available for connecting the winding. By arrangingthe conductor rails at this location, the space available at at leastone face of the stator can be completely used, thereby minimizing theaxial expansion of the magnetic non-active space of the stator.Furthermore, the conductor rails are located in the immediate proximityof the coil ends.

The conductor rails can all be arranged at one face end, whereas otherembodiments present at least one conductor rail on each face end. Inthis case, both face sides have one conductor rail for each phase, forexample. In order to simplify the arrangement, the conductor railsmounted on the same face side are grouped in one component. In anotherembodiment, several conductor rails are arranged next to one another andconnected with a conductor rail unit. In this case, the conductor railsare shaped like flat rings, for example, glued together on top of oneanother with insulating glue.

A conductor rail preferably comprises individual ring sectors. Indeed,if a conductor rail would be made in one part, e.g., sheet metal, muchof the material cannot be used for other conductor rails; manufacturingindividual ring sectors involves little waste of material.Alternatively, a conductor rail can also be manufactured by bending onesingle stick with an appropriate diameter.

Following another preferred embodiment, the winding comprises structuralparts. On one side, these structural parts windings allow for a highslot-filling factor. On the other side, a suitable embodiment andarrangement of the structural part allows for compact winding heads,thus creating, for example, winding head arrangements in which the spaceat the back of the stator remains available and can be filled with theconductor rails.

The conductor rails are preferably directly connected with thestructural parts of the winding. This is possible, in particular, whenthe conductor rails at the back of the stator are arranged below theslots and thus directly next to the winding heads. To this end, theconductor rails and/or structural parts building the coil ends arefavorably equipped with suitable connecting pieces, e.g. in the form oflinks, which can be stacked and connected (e.g. welded) together.

In the described embodiments, the coil or coil group ends connected withthe conductor rails are all arranged on the same side of the slotopenings as the conductor rails, i.e., in the direction of the depth ofthe slot. This is accomplished by connecting two spiral-shaped coils inseries, for example. At a certain moment, the current will then flowthrough one coil in the direction of the slot head, and through theother coil in the direction of the bottom of the slot.

The connections with the conductor rails are therefore either bothlocated at the slot head or the slot bottom. If the conductor rails arelocated on the same side, the coil ends can be directly connected withsaid conductor rails. Individual coils (not connected in series), on theother hand, would require a connecting piece placed square across thewinding heads from the head to the bottom of the slot, thus using axialspace.

In some of the described embodiments, several or all conductor rails arelayered next to one another in the lateral direction of the slots. Thisis particularly favorably when the conductor rails at the face side ofthe stator are located under the slot since they directly border thewinding heads, thus making it possible to connect them in the shortestway possible with the winding. This can be done with special structuralparts, in which the end of the slot bar is provided with an extendedlink reaching all the way to the conductor rails. “Slot bars” are thosewinding sections going through the slots and creating the coil sides;“connecting lines” are those sections at the face of the stator creatingthe end windings.

Said type of contact of the coil ends with coated conductor railsrequires contact between each coil end and only one of the conductorrails, in which at least one of the conductor rails preferably presentselevations on the side facing the slot openings—i.e., the windingheads—connecting the coil ends. If a coil is contacted and welded tosuch an elevation through a link at the end of a slot bar, for example,the link is kept at a distance from the other conductor rails at thesame time.

Alternatively, the conductor rails of other described embodiments arelayered in the direction of the slot depth. Both alternatives, i.e.,axial or radial layering of the conductor rails, preferably present atleast one conductor rail with links extending across the other conductorrails and with whom coil ends are connected. These links may possiblyreplace corresponding links at the coil ends, thus eliminating the needfor special structural parts connecting the winding of a structural partwinding. In case of an embodiment with conductor rails layered in aradial direction, the links run along the other conductor rails in aradial direction all the way to the winding heads, where they are alsokinked and connected with coil ends. In case of an embodiment withconductor rails layered in an axial direction, the links run over theother conductor rails, e.g. in an axial direction, thus creating alarger connection area on which the coil ends can be mounted andconnected, e.g. welded.

Following a preferred embodiment, at least two coils of the winding areconnected in series, whereby at least some connecting pieces createanother conductor rail with several insulated sectors between coilsconnected in series. This conductor rail can be arranged in a radialdirection between the winding heads and the remaining conductor rails,for example. They are preferably used in embodiments with each set offour coils connected in series and each pair of coils connected inseries with a connecting piece layered on the side of the conductor railturned away from the winding heads. The connecting pieces between twopairs of coils connected in series may then be arranged in such a waythat a maximum of one connecting piece runs parallel with each spot ofthe perimeter of the stator. This way, the connecting pieces of a ringcan include a series of mutually insulated sectors. This ring shallpreferably be integrated in the conductor rail unit.

Following another embodiment, the winding comprises several overlappingcoils composed of the slot bars located in the slots and the connectinglines located at the face sides of the stator, whereby the connectinglines are flatter than the slot bars and the connecting lines areinterlocked by overlapping coils, and therefore layered.

Below follows a more detailed description of the winding shown in thepreferred embodiments. The described conductor rails, can of course alsobe used for connecting any other polyphase windings.

The winding preferably comprises at least in part of L-shaped structuralparts (L structural parts), in which one leg of the L structural partcreates a slot bar, and another leg creates a connecting line basicallyrunning in the direction of the winding and perpendicular thereto. Byconnecting the bare end of the slot bar of a structural part with thebare end of a connecting line of another structural part, a connectedwinding is created (in the case of a preferred embodiment, this windingcomprises spiral-like coils), in which two connected L structural partseach time create one coil winding.

Following another embodiment, the complete winding can be composed ofonly a few different structural parts. One embodiment uses only twodifferent types of L structural parts—possibly besides the connection ofthe coils—whereby the legs of the connecting lines flatter than those ofthe slot bars. A first embodiment creates a connection within one andthe same winding arrangement, whereas a second embodiment creates atransition of one winding arrangement into the next. The end of eachslot bar leg of a preferred embodiment presents a flattened link; theflattened link and the flatter leg of one type of L structural part areboth located at the same level as the bottom of the slot bar leg. A type1 structural part presents one half of a coil winding, whereas a type 2structural part completes the winding. Moreover, the connecting line ofsaid structural part leads this coil into the next winding arrangement.By alternately connecting structural parts of types 1 and 2, aspiral-like coil is created.

Other structural part types can possibly be used in order to connect theabove winding. It can, for example, include another structural partconnecting two coils connected in series. This structural part ispreferably U-shaped and made of two slot bar legs and a connecting linesection, which is flatter than the slot bar leg. Another structural partcan be used to connect the coil with a power supply. Certain embodimentsuse another type of L-shaped structural part with a connecting line legwhich is flatter than the slot bar leg and having an extended flattenedlink at the end of the slot bar leg. In other embodiments, said linksare located directly at the conductor rails, allowing to connect thewinding with a standard type 1 or 2 structural part.

In yet another embodiment, the connecting lines of overlapping coils areinternally staggered with at least one complete winding. In saidembodiment, the connecting lines are arranged in layers and preferablyshaped flatter than the slot bar, e.g. so flat that the arrangement ofconnecting lines belonging to a winding arrangement of the differentoverlapping coils is not thicker than one slot bar. The coils can becomposed of any number of windings when several such arrangements ofinternally staggered connecting lines are placed on top of one another.

The examples shown present a winding with interlocked connecting linesmade of L-shaped structural parts. In other embodiments (not shown),such winding can be made of individual slot bars and connecting lines (Istructural parts), C-or U-shaped structural parts, or structural partsalready comprising a complete winding (O structural parts) when beingmounted, for example.

In order to make the winding at the face as space-saving as possible, ithas been deemed favorable to create the winding following a windingscheme with the fewest possible number of staggered winding headsrunning beside one another. A simple example would be an alternatecurrent winding with one slot per pole and branch (single-hole winding),having only two staggered winding heads at a time. The situation isdifferent, for example, for windings with multiple slots per pole andbranch (multiple hole windings), used to create a more favorable fieldflow, preferably similar to a sinus-shape. A two-hole alternate currentwinding comprises four staggered winding heads on each face side, forexample.

The winding of the described embodiments has a fractional pitch in orderto reduce the number of winding heads rotating past one another inmultiple hole windings. The coil width of a fractional pitch winding issmaller than the pole pitch. The “pole pitch” refers to the distanceexpressed in the slots between two magnetic poles. The slot widthindicates the required number of slots between the first and the secondcoil side. The preferred embodiments have a pole pitch 6, but a coilwidth of only 5. This means that the end windings of the coils areshorter than those in a non-fractional pitch winding since they onlyhave to bridge four instead of five slots. Consequently, the windingsections at the faces are shorter and therefore take up less space, thusreducing the resistance loss. In the case of the rotary two-slot windingshown, the pitch of the winding allows to run only three instead of fourend windings in an interlaced pattern, for example. This type offractional pitch winding pattern is extremely favorable for structuralpart windings in the sense that it allows for a compact end windingarea. It can, however, be used for windings made of wire arrangementoffering corresponding advantages.

The windings shown in the preferred embodiments have several spiral-likecoils, in which two coils are connected in series in such a way that thecurrent in one coil runs through the spiral in the direction of the slothead, and the other in the direction of the bottom of the slot. Theconnecting lines of the coils are flatter than the slot bars layered ontop of one another at a slant angle in respect to the connecting linebetween both slots, and connected with the slot bars. A spiral-shapedcoil is formed, for example, when the connecting lines from one faceconnect slot bars of the same arrangement, and the connecting lines onthe other face connect slot bars from radial by superimposed layers.This type of winding can be made of L-structural parts, for example. Inprinciple, other structural parts (e.g., U-, C-, I- or O-shaped) orwire-wound coils can also be used.

The serial connection of the two spiral-like coils shown allows theconnections to the conductor rails to be arranged either at the bottomor at the top of the slot, in other words, both on the same side of theconnecting line. This is especially favorable when the conductor railstack is also placed on this side of the connecting line.

By and large, the described embodiments use the space at the face of astator in a space-saving way, thus particularly allowing for a limitedaxial expansion of the magnetic non-active volume of the stator.Moreover, the preferred structural part winding has a high space factor,resulting in a high torque density. The preferred embodiments aretherefore especially suitable for motor vehicle crankshaftstarter-generators. This involves an electric machine serving as astarter and generator, and located concentrically on the crankshaft of acombustion engine and firmly connected with this winding, preferablywithout interstage transmission. Because of the limited rebound space,the axial expansion of a starter-generator is rather small; on the otherside, the direct starting method requires an elevated torque.

Returning to FIGS. 1-7, these figures show different conductor railembodiments. The conductor rails run around the stator allowing toconnect several coils or coil groups placed in parallel along theperimeter. The current flow through the current supply of conductorrails is generally higher. Therefore, the diameter of the conductorrails is relatively large in order to minimize the resistance losses.Consequently, the conductor rails take up a lot of space. In order tolimit the axial expansion of the stator as much as possible, theconductor rails in this area in the examples shown are arranged in aradial way next to the slot openings on one face of the stator. Thesurface at the face remains bare anyway in the compact winding headarrangement described above, and this space-saving arrangement cantherefore be used for the current supply. The conductor rail sets aretherefore particularly suitable for connecting the winding describedabove. However, they can be combined with any winding, in principle.

FIG. 1 shows an example of an arrangement of the conductor rails for arotary current winding according to a first embodiment. As mentioned,the conductor rails are arranged in the direction of the slot depthbelow the winding heads and in this case connected with connections 49with the rotary current source. The conductor rails shown in FIG. 1 arelaterally layered on top of one another, i.e., the axial direction ofthe slots, in such a way that each conductor rail ends up directlyadjacent to the radial inside of the winding heads. The joints 60, 62connecting the branches with the conductor rails are therefore arrangedon the radial inside of the conductor rails. The winding can thereforebe directly connected, for example welded or soldered, to the conductorrails 40, 42, 44, 46 without any other connecting pieces, for examplewhen the winding consists in part of special structural parts 3 withextended joint bars 26 at the slot bar end reaching all the way to thejoints 60, 62 (see FIG. 10).

It should be guaranteed, however, that each extended joint bar 26contacts only one of the conductor rails 40, 42, 44 or 46. For thispurpose, the joints 62 of the conductor rails 42, 44, 46 are equippedwith an electric insulating coat with windows, offsetting one another insuch a way that each joint bar 26 contacts no more than one window.According to another variant shown in FIGS. 1, 3 and 4, the currentrings at the contact points 62 show elevations, so-called welding bulges63, sticking out radially to the inside. If an extended joint barcontacts a welding bulge 63 and is welded to it, the joint bar is keptat a distance of the other conductor rails at the same time. The weldingbulge 63 is stamped for example into the conductor rails 42, 44, 46 bypressing the conductor rails 42, 44, 46 in an axial direction at thosespots where a welding bulge 63 is required, thus creating a bulge 63from displaced material on the radially inwards facing side of theconductor rail. The displaced material could, for example, be shapedlike a protruding banner (see FIG. 4).

If need be, the winding is not only connected with the conductor railsfor the current supply, but also with a conductor rail connecting threebranches, the so-called star point. Alternatively, the branches can alsobe delta connected, thus eliminating the need for conductor rails forthe star point. Since the current in the three phases of a rotarycurrent source are de-phased by 120° to one another, the sum of thecurrents flowing in the star point nearly equals zero at any time. Forthe sake of saving space, the conductor rail for the star point 40therefore has a smaller cross-sectional area than the conductor rails42, 44, 46 for the current supply, i.e., the cross-sectional area isaxially thinner than the other conductor rails 42, 44, 46. The starpoint conductor rail 40 in the example shown in FIG. 1 is too thin toweld a structural part of the winding on the inner radial area of astructural part of the winding. Therefore, it has joint bars 60 insteadof welding bulges 63 extending in an axial direction over the radialinner area of the other conductor rails. The extended joint bar 26 of astructural part 3 could be welded on these joint bars 60, for example.For the sake of clarity, FIG. 2 presents the conductor rail for the starpoint 40 with the joint bars 60 without the other conductor rails.

The conductor rail unit shown in FIG. 1 is suitable for connecting athreephase winding with any winding layout. The conductor rail unitshown in FIG. 3, on the contrary, is very suitable for connecting therotary current winding with four coils each connected in series. It hasthe same components as FIG. 1, in particular three axially layeredconductor rails 42, 44, 46 connecting the winding with the electriccurrent supply. These conductor rails all have joints 62 shaped aswelding bulges 63, as well as a conductor rail 40 for the star point,which is equipped with joint bars 60 extending over the radial interiorsurface of at least one of the conductor rails. It additionally hasanother rail, a sector piece conductor rail 48 arranged on the radialinner side of the conductor rail set; the joints 60 and 62 of theremaining conductor rails 40, 42, 44, 46 are accessible through thecorresponding recesses in the sector conductor rails 48 and put incontact with the winding. The sector piece conductor rail 48 is notcontinuous, but comprises sector pieces insulated electrically from oneanother. They create the connecting pieces marked as 48 in the windingarrangement of FIG. 19 between two pairs of coils connected in series.For this purpose, the extended joint bars 26 of structural parts 3 ofthe coils 52 and 54 belonging to the different coil pairs are weldedwith both ends of a sector 48.

Following yet another embodiment, the conductor rails are layered in aradial direction as shown in FIG. 5 a, and not in an axial direction.Only one conductor rail 46 is arranged directly at the winding heads inthis arrangement, whereas the other conductor rails 42, 44 do not havedirect access to the winding. Therefore, all conductor rails have jointbars 61 protruding radially to the inside over other conductor rails orover the winding heads, if necessary. The winding is connected forexample by bending the end of these joint bars 61 to the inside, andwelding the extended joint bar 26 of a structural part 3 to the bentend. This embodiment also allows for arranging a conductor rail 48subdivided in sectors in a radial direction on the inside of theconductor rail unit, or arranging a conductor rail for the star point ina radial or axial direction over the other conductor rails 42, 44, 46.

The conductor rails could be made of rings cut out of sheet metal, forexample. This results in quite a bit of waste however. Therefore, it ispreferred to make the conductor rails of bent bars with an appropriatecross-section or individual ring sectors. FIG. 6 shows such a conductorrail 40, 42, 44, 46 made of individual ring sectors 45. Press fitting ispreferred method to connect the ring sectors 45 at the connecting parts43, whereby oversized extensions 47, for example, are pressed incorresponding recesses in the sector ends. This results in the jointsbetween the sector being airtight, thus protecting them againstoxidation. The conductor rails are favorably turned into a unit in sucha way that the joints between the sectors of interlaced conductor railsare offset, thus increasing the stability of the conductor rail unit.

FIG. 7 shows such a conductor rail unit comprising four ring-shapedconductor rails, 40, 42, 44, 46, composed of individual sectors 45. Thejoints 43, 43′ between the sectors of the different conductor rails areoffset to one another. In the example shown, for example, the joints 43between the sector of the conductor rails located on top of the drawingare located directly over the joints 43 between sector of the secondconductor rail from the bottom, whereby joints 43′ between sectors ofthe second conductor rail from the top and the bottom are offset by onehalf sector length. This enhances the mechanical stability of theconductor rail unit. The embodiment of FIG. 7 only shows the topconductor rail 40 for the front links 61; in other embodiment examples,the remaining conductor rails are also provided with corresponding linkscontacting the coil ends.

There are different methods for connecting the conductor rails 40, 42,44, 46 with a conductor rail unit. On one side, the connection securesthe mechanical stability and simplified arrangement of the conductorrail unit; on the other side, it can also create an electric insulationbetween the conductor rails at the same time. This is the case, forexample, when the conductor rails are connected with a glue containing afiller such as glass beads, which keep the conductor rails separated. Analternative insulation means would consist of placing paper between therails, subsequently gluing it with an appropriate glue, and pressing theconductor rails together. The glue is preferably temperature-resistantin order to avoid possible heating of the conductor rails because ofresistance losses. Following another alternative, the conductor railshave an insulating coat such as a back coat. This is a coat withglue-like characteristics when heated. Each conductor rail is coatedwith a back coat, assembled into one conductor rail unit andsubsequently heated, thus melting together the different coats of theconductor rails.

Below is a description of embodiments of windings, which are preferablyconnected with the described conductor rails. These windings comprise,for example, a structural parts winding mainly composed of L-shapedstructural parts. The conductor rails described above are of course alsosuitable for connecting any multiphase winding.

FIGS. 8-11 provides a detailed description of all the structural partsused for the preferred winding.

FIG. 8 a shows an exploded view of a first type of L-shaped structuralpart. One leg 8 a of the L-shaped structural part 1 creates a slot 8 inthe finished winding, and the other leg 6 a is located at the face ofthe stator and connects slot bars 8 located in different slots. The slotbars and joints are generally marked with reference numbers 8 and 6,respectively, whereas the slot bar legs and connecting line legs of thedifferent structural parts are referred to as 8 a, 8 b, and 6 a, 6 b,respectively.

The connecting lines 6 are flatter and wider than the slot bars 8, asshown in the cross-sections of both legs 6 a and 8 a in FIG. 8 b. Theslot bars 8 actually have a thickness H and a width B, whereby the widthB in the embodiments shown has been determined to allow for severalslots bars in one slot next to one another, i.e., at the same heightfrom the slot bottom. The thickness h of the connecting line 6, forexample, is one third of the thickness H of the slot bar 8, whereas thewidth b is about three times the width B of the slot bar 8. This meansthat the cross-section of the line in both legs of the structural partshown is about the same.

The structural part 1 has a flattened joint bar 10 a at the bare end ofthe slot bar 8 a. The joint bar 10 a of the first type shown in FIG. 8 alies at the same height as the connecting line 6 a, i.e., on the bottomside of the slot bar leg 8 a in the drawing. This means that the(invisible) bottom side of slot bar 8 a of the connecting line 6 a and aslot bar 8 a located close to the transition region 12 of the joint bar10 a are at the same level. The thickness of the transition region 12 ofthe joint bar 10 a is about the same as that of the connecting line 6 a,i.e., approx. one third of the thickness of the slot bar. The far end ofthe joint bar 10 a presents a connecting region 13, which is flattenedeven more compared with the transition region 12, i.e., to about onesixth of the thickness of the slot bar. The transition between regions12 and 13 is made with a step at the lower side of the joint bar 10 a.The connecting region 13 thus leaves a clearance at the bottom side ofapprox. one sixth of the thickness of the slot bar compared with theheight of the bottom side of the slot bar 8 a.

Two structural parts are connected by placing the connecting area 13 ofthe joint bar 10 a at the end of the connecting line of a secondstructural part. The connecting area 13 is then connected, e.g., welded,to the connecting line of the second structural part. Therefore, theconnecting region 13 of joint bar 10 a does not have an insulating coat,just like the joint 16 at the end of the connecting line 6. This ismarked in the drawing with a shaded line. Structural part 1 and allother structural parts, which are not marked with a shaded line have aninsulating coat. In order to make sure that the connecting layer locatedin the densely packed end winding area between two structural parts isnot thicker than a connecting line 6, the joint 16 of the connectingline 6 a has been flattened to about half the thickness of theconnecting line 6 a. This way, the joint bar connecting region 13 can beplaced and welded to a joint 16 without exceeding the thickness of theconnecting line 6 at the connecting region. Since the thickness of thetransition region 12 (which has been kept as short as possible) and theactual connection is only about one third of the slot bar 8 a, it comeswith a cross-section contraction. This is accepted in favor of a denselypacked end winding arrangement of the connecting line. The transitionregion 12 can be advantageous since it creates a distance between theslot bars and the end winding. The cross-section of the line should beas big as possible. The transition region 12 could also be arranged as acontinuous transition between the slot bar and the connecting region 13.In other embodiments where the transition region 12 has been omitted,the connecting region 13 is directly connected with the slot bar 8.

FIG. 9 shows a second type of a L-shaped structural part 2 used tocreate a complete winding of a spiral coil in combination with the firsttype. Structural part 2 basically has the same embodiment as structuralpart 1, i.e., the lengths and the cross-sections B—B and A—A of theconnecting lines 6 a, 6 b and joint bars 8 a, 8 b of both structuralparts are the same. Structural part 2 also has a flattened joint bar 10b at the bare end of the slot bar 8 b. Contrary to the slot bar 10 a ofstructural part 1, the flattened joint bar 10 b is not located at thesame height as the connecting line 6 b, but offset with the opposingarea of the slot bar 8 a. The joint bar 10 b of structural part 2 isactually located at the height of the side (located on top in FIG. 9) ofslot bar 8 b, whereas the connecting line 6 b—just as in structural part1—is located at the same height as the bottom side of the joint bar 8 b.For the rest, the joint bar 10 b of structural part 2 is laid out thesame way as joint bar 10 a of structural part 1, i.e., it has atransition region 12 directly following the slot bar 8 b and about asflat as the connecting line 6 b, and yet another flattened connectingregion 13 at the outer end of the joint bar 11. This region 13 is soflat that its thickness together with the thickness of the flattenedjoint 16 of a connecting line 6 is about the same as the thickness H ofa connecting line 6. The step between transition regions 12 and 13 islocated at the downwards pointing side of the entire joint bar 10 b insuch as way that the top side of the entire joint bar 10 b is located atthe same height as the top side of joint bar 8 b.

FIG. 10 shows a third type of L-shaped structural part 3, used toconnect the winding with the conductor rails. Structural part 3 isbasically the same as structural part 1, but comes with an extendedjoint bar 26 instead of joint bar 10 a. This extended joint bar 26 isconnected, e.g., welded, to a conductor rail and is therefore notinsulated. The thickness of slot bar 26 is preferably the same as thethickness h of a connecting line 6. Structural parts 3 are favorablylocated in the lower winding arrangement of the slots, bordering theextended joint bars 26 directly to the conductor rails placed below theslot bars, if need be. Another option would be to place the structuralparts 3 in the top winding arrangement.

In another preferred embodiment, the joint bars are placed on theconductor rails in order to connect the winding with the conductorrails. In this case, no special structural parts 3 of the third type areneeded and the joint bars 10 a of the structural parts 1 of the firsttype, for example, are welded on the extended joint bars 26 of theconductor rails.

Finally, FIG. 11 shows a type of U-shaped structural part used to createa serial switch for two spiral-shaped coils of one winding. The U-shapedstructural part 4 has two slot bar legs 8 b, 8 b′. The length and thecross-section A—A of these slot bar legs are the same as those of theslot bar legs 8 a, 8 b of structural parts 1 and 2. Both slot bars 8 b,8 b′ have a flattened joint bar 10 b at the bare end. This joint bar 10b is located in the drawing at the topside of the slot bar 8 b, 8 b′,respectively, and therefore corresponds with the slot bar 10 b of theL-structural part 2. The connecting line 7 connecting both slot bars 8b, 8 b′ has the same cross-section B—B as the connection lines 6 a, 6 bof structural parts 1 and 2. It is, however, one slot length longer. Ifthe connecting lines 6 a, 6 b of the structural parts of the first andthe second type are, for example, long enough to create a coil with slotbars 8 within a distance of five slots, the connecting line 7 of theU-structural part is extended by connecting two coils, here for examplein such a way that both slot bar legs 8 b, 8 b′ end up at a distance ofsix slots from one another. Another typical detail of the connectingline 7 is that it is not located at one and the same level relative toboth slot bar legs 8 b, 8 b′. It is rather located at the height of thetop side (in the drawing) of a slot bar leg 8 b on one side, yet on theother side at the height of the bottom side of the other slot bar leg 8b′. If both slot bar legs 8 b, 8 b′ of a U-structural part in a finishedwinding present in the same winding arrangement, the U-structural partconsequently lies at a slight slant angle with both slot bars 8 b, 8 b′to the connecting line between both slots. The ends of the connectingline legs of these L-shaped structural parts are flattened, as indicatedwith a welding 27. The U-shaped structural part can be made of twoL-shaped structural parts, for example, with flattened areas at the endof the connecting line legs. These flattened areas are placed on top ofone another and welded together.

Next, the construction of a winding with overlapping coils made ofL-structural parts will be described as per FIGS. 12 through 14. Thesefigures show the composition of the bottom winding layer with fewstructural parts. For the sake of simplicity, the structural parts arepresented without a stator lying down on a flat surface. In case of astator body of a radial field machine, the structural parts would belocated on the interior sheath surface of a cylinder. FIG. 12 showsthree type 3 L-shaped structural parts with extended joint bars. Thestructural parts 3 are located in the winding arrangement right at thebottom of the slots and placed in an offset pattern two slot lengthsapart, so each second slot of slot bar 8 a contains one structural part3. The extended joint bars 26 are all located at the same face of thestator body and connected with the conductor rails (not shown)underneath. The connecting lines 6 on the other side of the stator bodyare placed on top of one another in a scaled pattern, thus creating alayer 28 of connecting lines. Inside the layer of connecting lines 28,the connecting lines are layered in such a way that the bare end isalways located in the upper part of this layer and the joint 16 isexposed and accessible, whereas other connecting lines 6 a cover theother end. The transition between the connecting lines 6 a and the slotbar 8 a of the same L-structural part 3 is covered with other connectinglines 6 a. The transition between the connecting lines 6 a and the slotbar 8 a of the same L-structural part 3 is located in the covered area.

As the drawing shows, the connecting layer 28 contains three connectinglines 6 a on top of one another. Since the thickness h of the connectinglines 6 a in the embodiment shown is about one third of the thickness Hof the slot bar 8 a, the connecting line layer 28 is nowhere higher thanthe corresponding layer of slot bars 8 a.

In the example shown, the connecting lines 6 a connect slot bars everyfive slots, as clarified below. In other embodiments (not shown), theconnecting lines connect slot bars at a bigger or smaller distance sothere are also more or less three connecting lines on top of one anotherin one connecting line layer. The thickness h of the connecting lines 6is favorably selected in such a way that the thickness of eachconnecting line layer 28 corresponds with the thickness H of a slot bar8. Other embodiments, which do not specify a certain structuralconnecting part for the conductor rails, use structural pieces of thefirst type in the first arrangement steps following FIG. 6.

Once each slot has a structural part 3 of FIG. 12, each remaining slotis filled with one structural part of type 2 in such a way that itsconnecting line 6 b ends up on top of the connecting lines 6 a of thestructural parts 3 inserted previously and located on the opposing faceof the stator (see FIG. 13). The connecting region 13 of the flattenedjoint bar 10 b of structural part 2 thus ends up on the flattened joint16 of the connecting line 6 a of structural part 3. The structural part2 is connected with structural part 3 in this location, i.e., by weldingwith a laser beam. A laser beam with adequate energy is pointed at theexposed surface 14 of the connecting region 13 of the joint bar 10 b,melting the material of the connecting region 13 of the joint bar 10 band merging it with the underlying joint 16 of the connecting line 6.Alternatively, there is a groove in area 13 of the joint bar 10 b,enabling to point the laser beam directly through this groove at theedge between the end of the joint bar 13 and the joint 16 underneath. Inthis case, the laser beam does not have to melt the entire thickness ofthe end of the joint bar 13. The extended links 26 of the structuralparts 3 may also be welded to the conductor rails.

Since the connection area 13 of the joint bar 10 b of structural part 2is located at the level of the top of the slot bar 8 b as clarified inFIG. 9, the slot bar 8 b of structural part 2 ends up in the samewinding arrangement as the slot bars 8 a of the structural parts 3 whenit is placed on top of the connecting region of the connecting line 6 a.This eliminates the difference in height caused by the scaled pattern ata slant angle of the connecting lines 6 a in the connecting line layer28.

At the opposite face, the connecting line 6 b of the structural part 2is also placed at a slant angle, i.e., at the covered end at the sameheight as the extended joint bars 26 of structural parts 3. From thispoint to the bare end, it is only covered over this joint bar.

FIG. 14 shows the same winding arrangement as FIG. 13, with anadditional structural part 2′ corresponding with structural part 2.Structural part 2′ is connected the same way as structural part 2, i.e.,with the end of its joint bar end area 13 at the end of its slot bar leg8 b′ with the joint 16 of structural part 3. It is connected on theopposite side with the connecting line 6 b′ in a layered scale-likepattern over the connecting line 6 b of structural part 2 in such a waythat the joint 16 ends up over the slot bar end of structural part 3connecting the joint bar end area 13 of structural part 2′.

A complete winding arrangement of slot bars 8 is created by placingadditional structural parts 2 and 3 in each second slot in accordancewith FIG. 14. The connecting lines of structural parts 2 and 2′,respectively, then create a second connecting line layer 30 similar tolayer 28 on the other face. Each bare end of connecting lines 6 a, 6 bof the structural parts 2, 3 faces upwards in these layers in such a waythat the joints 16 are not covered by connecting lines of the samelayer. Each connecting line layer 28 and 30 is layered at a slant anglein such a way that the connecting line 6 b (in the exploded view of thedrawing) runs from the bottom left to the top right, and the connectinglines 6 a from the bottom right to the top left.

Welding structural part 2 to the matching structural part 3 creates acomplete winding of a spiral shaped coil. The connecting line 6 b ofstructural part 2 layered at a slant angle takes the winding to thenext-higher winding layer. The spiral is extended by putting astructural part 1—not shown in FIG. 14—on structural part 3 of the firstwinding. This creates the beginning of the new winding layer. Theconnecting area 13 of joint bar 10 a thus places structural part 1 onthe joint 16 of the corresponding structural part 2 and is connectedwith it as described above. Since the slot bar 10 a of structural part 1is located at the level of the bottom of the slot bar 8 a of structuralpart 1, the height difference created in the connecting line layer 30resulting from the slant layering is not leveled out, but ends upcreating a spiral instead. Structural parts of type 1 are placed on allstructural parts 3 in order to create a complete winding. These type 1structural parts are again welded on the corresponding joints 16 of thestructural parts 2. Additional structural parts 2 are placed in theremaining slots, i.e., each second slot on top of the structural parts2, and then welded to the joints 16 of structural parts 1, thuscompleting this second winding arrangement. The connecting lines ofstructural part 1 create another connecting line layer 28. Thecomposition of this layer is the same as the connecting line layer 28 ofstructural parts 3 shown in FIG. 14. Once the second winding layer hasbeen installed and connected, several interlaced coils each having twowindings with connecting lines staggered in one another have beencreated.

FIG. 17 shows a diagrammatic view of the staggering of the connectinglines of interlaced coils. This figure shows a diagrammatic top view ofthe faces of a spooled stator. The face surface of the connecting lines6 b is marked in a simplified way with lines. The connecting lines 6 bare arranged in four slant layers 30 on top of one another. Theconnecting lines 6 b of the different branches are marked with differentlines, e.g., the connecting lines of branch V with continuous lines, theconnecting lines 6 b of branch W with dash-dotted lines, and theconnecting lines of branch U with a dashed line. The different branchesalternate within one connecting line layer 30, creates Spiral shapedcoils 50, 52, 50′, 52′, 50″, 52″ with staggered connecting lines arecreated by layering multiple similar layers and the correspondingconnections between the structural parts of these layers. Eachconnecting line 6 b of a layer 30 belongs to another coil. Theconnecting lines of branch V, for example, belong to coils 50, 52, thoseof branch W to coils 50′, 52′, and those lines of branch U to coils 50″,52″. Coil 52″ overlaps coils 52, 52′ on one side, and coils 50, 50′ onthe other side.

On the opposite face, the connecting lines 6 a are arranged accordingly,with the difference that each connecting line 6 a of the layer 28connects slot bars from winding layers lying on top of one another,which results in them passing into the next-higher winding layer aftereach winding.

The end winding arrangement of FIG. 17 can also be used for windingswhich are not composed of L-structural parts, but of any other randomstructural parts. In principle, the end windings of wire-wound coils canalso be staggered instead of evading in bunches at the faces. Eventhough FIG. 17 shows a three-phase two-slot winding, any random windingof an alternating or direct current generator can be created in such away that the connecting lines of interlaced coils are staggered.

Just like FIGS. 12 through 4, FIG. 15 shows a part of the winding layerlocated under the slots. The figure no longer shows an idealized leveleddeveloped view, but a cutout of a bent stator 32 of a radial fieldmachine in an interior armature embodiment (or an armature in anexterior armature embodiment) with structural parts 2, 3 placed in theslots 34. In order to make the actual winding better visible, theembodiment only shows the two face sides of the stator body 32. Thestator body 32 is solid of course, and typically made of electric sheetsaxially layered on top of each other. This means that each face of thestator body 32 corresponds with the outer sheets of the armaturestampings.

Structural parts 2, 3 are located inside the slots 34 directly above thebottom of the slot. The head 36 of the slots 34 is narrowed so theL-structural parts 2 and 3 can only be slipped in the slots in an axialdirection. The face side seen from the spectator's point of view hasalready been put in a layer of structural parts 3, and three structuralparts of type 2 have been put on the opposite face side.

Next, a manufacturing example of the method used to create a circuit ofcoils connected in series is clarified on the basis of FIG. 16. Saidfigure shows a diagrammatic top view of the slotted side of a stator orarmature—one should picture the stator or armature body cut open againand wound off in one tier. The narrowing of the slots at the slot headis not shown here, which allows a full view of the top winding layer inthe slots. The slots are all numbered from 1 through 12 since thewinding arrangement used in this example is repeated every 12 slots.

In the stator shown in FIG. 16, L structural parts 1, 2, and, ifnecessary, 3, are placed in the slots of the stator or rail of FIGS.12-14 and the number of layers is sufficient to fill all of the slotswith slot bars, except for the top slot bar. Finally, only type 4U-shaped structural parts instead of type 2 L-shaped structural partsare placed at the bottom part of the face. Each U-structural part 4marked with a shaded line each has two slot bars 8 b and 8 b′ located inthe slots 2 and 8, 4 and 10, 6 and 12. This means that there is a slotbar leg of a U-structural part in every other slot. The connecting line7 of the U-structural parts are also layered on top of one another in ascaled pattern on the lower face of the stator, just like the connectinglines 6 of the L-structural parts. The connecting lines 7, however, areall one slot distance longer than the connecting lines 6 of theL-structural parts. Consequently, the flattened joint bars 10 b of theslot bars 8 b, 8 b′ of the U-structural parts all end up on the bareends of coils belonging to different connecting lines 6 a of structuralparts 1, and are welded with a laser beam in this final step.

Inside each U-structural part, two spiral shaped coils are connected inseries. The following is a detailed description of this in reference toFIG. 17. As mentioned above, FIG. 17 is a highly diagrammatic top viewof one face side of a spooled stator. The face side in questioncorresponds with the lower face shown in FIG. 16. FIG. 17 shows the backof the connecting lines 6 b placed on top of another in several layers30. For the purpose of illustration, the current direction in one of thebranches has been marked with arrows in the drawing. The branch U markedwith a continuous line starts at point A with a connection to aconductor rail. From there, the branch is guided into a spiral shapedcoil 50 to the slot head over four winding layers or four connectingline layers 30, respectively. The dotted line represents a connectingline 6 on the opposite face side of the armature. This connecting line 6connects a U-structural part with the connecting line 7 running over thevisible face side. Two coils 50 and 52 with an identical arrangement areconnected in series through the U-structural part in such a way that thecurrent flows through both coils in an opposite direction, in thedirections of the arrows. Consequently, the current in the spiral shapedcoil 52 depicted flows from the slot head to the slot bottom, whereas incoil 50, it flows from the slot bottom to the slot head. The branch isconnected with the star point at point B. The other branches, depictedwith dashed or dash-dotted lines, respectively, mark connections withthe conductor rails as well as corresponding U-structural parts withconnecting lines 7, which have not been marked in FIG. 17.

FIG. 18 shows the winding arrangement for the winding shown in FIGS. 8through 17. It shows how the individual coils are distributed over theslots of the stator, whereby this winding arrangement has only one coilside in each slot (single-layer winding). The winding arrangement isrepeated every 12 slots. The winding is laid out as a three-phasewinding (rotary winding) with two slots per pole and branch (two-slotwinding). This results in a pole pitch of six, i.e., the distancebetween two poles is six slots. In case of a full-pitch winding, thecoil width, i.e., the distance between both coil sides of a coilexpressed in slots full-pitch winding, therefore also equals six. Thecoil width of the winding shown in FIG. 18, however, is smaller than thepole pitch, i.e., and equals five. Therefore this is a so-calledfractional pitch winding. The fractional pitch results in the windingheads of no more than three coils are guided along one another at thefaces of the stator. For the winding embodiments described above, thismeans that a compact winding head arrangement is obtained when thethickness h of the connecting line is one-third or smaller than thethickness H of the slot bars.

A branch V in FIG. 18 is printed in bold for the sake of clarification.The other branches U, W run accordingly. Branch V consists of two coils50, 52 connected in series, which are presented here in a simplified wayas closed rings whereas they actually are spirals with eight windings,for example. On one side, coil 50 is connected electrically with theconductor rail 44 for branch V, and on the other side with the coil 52via a connecting piece 7 (which could be a U-structural part, forexample) bridging six slots. This is connected with the conductor railmarked with a Y for the star point 40. The immediate current directionhas been marked with arrows. Both coils 50, 52 are located inneighboring slots with their coil sides facing each other, in such a waythat the current in both neighboring slots flows in the same direction.Each time, there are four coil sides of coils from other branchesbetween the coil sides of a coil 50, 52.

The arrangement of the winding heads does not become clear from thewinding arrangement of FIG. 18. If, however, the connecting lines arelayered in a compact way as described above, there is hardly any spacingin the densely packed winding head arrangement. Therefore, theconnecting pieces 7 necessary to connect two coils in series are eitherconveniently located at the slot head or at the slot bottom, i.e., atthe edge of the winding head package. If the winding basically consistsof spiral shaped coils (i.e., coils in which the connecting lines do notoverlap in a radial direction), a connecting piece 7 connects two coils50, 52 in series at once in such a way that the current flows in thedirection of the slot head in one coil, and in the direction of the slotbottom in the other coil. However, since the above described layering ofthe connecting line is identical for both coils 50, 52, connecting piece7 connects both coils 50 and 52 in series in such a way that the currentflows in an opposite direction, i.e., negative phase sequence, throughboth spirals. As a result of this serial connection, the connectionsbetween the branches and the conductor rails for the current supply 42,44, 46, as well as for the star point 40 automatically all end up on oneradial side of the winding head package, actually on the other side ofthe connecting pieces. The conductor rails are also conveniently locatedon this side.

An alternative consists of connecting four coils in series or anothereven number each time, as shown in FIG. 19. The winding arrangement ofFIG. 19 is the same as the one of FIG. 18, with the only difference thattwo pairs of coils connected in series are again connected in serieseach time with another connecting piece 48. The connecting pieces 48 canbe laid out the same way as the connecting pieces 7; following anotherlayout, they create sectors of an additional conductor rail.

FIG. 20 shows a winding embodiment in a stator of an electric radialfield machine with a conductor rail packet, corresponding with the oneshown in FIG. 5. The space-saving use of the area at the face of thestator 32 becomes very clear here, as well as the staggered arrangementof the coils overlapping the connecting lines 6.

All publications and existing systems mentioned in this specificationare herein incorporated by reference.

Although certain products constructed in accordance with the teachingsof the invention have been described herein, the scope of coverage ofthis patent is not limited thereto. On the contrary, this patent coversall embodiments of the teachings of the invention fairly falling withinthe scope of the appended claims either literally or under the doctrineof equivalents.

1. A winding arrangement for a stator of an electric machine with apolyphase winding having a plurality of phase branches, comprising:coils or coil groups, and conductor rails with at least one terminal, inwhich each phase branch comprises a plurality of coils or coil groupsconnected in parallel; in which the conductor rails are located at leastpartially around the stator; and in which at least one end of the coilsor coil groups connected in parallel is connected with one of theconductor rails in such a way that said conductor rail forms a currentconductor connecting the terminal with the parallel-connected coils orcoil groups of a phase branch.
 2. The winding arrangement of claim 1, inwhich the electric machine presents a stator with slots creating lateralslot openings in the stator and having a slot depth, and in which theconductor rails are placed at one or both face sides of the stator inthe direction of the slot depth below the slot openings.
 3. The windingarrangement of claim 1, in which a plurality of conductor rails isarranged next to one another and connected with a conductor rail set. 4.The winding arrangement of claim 1, in which at least one conductor railis composed of individual ring sectors.
 5. The winding arrangement ofclaim 1, in which the winding is composed of structural parts.
 6. Thewinding arrangement of claim 5, in which the conductor rails aredirectly connected with structural parts of the coils.
 7. The windingarrangement of claim 2, in which the ends of the coils or coil groupsconnected with the conductor rails are all arranged in the direction ofthe slot depth and at the same side of the slot opening as the conductorrails.
 8. The winding arrangement of claim 2, in which the slots run ina lateral direction, and a plurality or all of the conductor railsis/are layered next to each other in the lateral direction of the slots.9. The winding arrangement of claim 8, in which at least one conductorrail comprises elevations connecting the coil ends on the side facingthe slot openings.
 10. The winding arrangement of claim 2, in which aplurality or all of the conductor rails is/are layered on top of oneanother in the direction of the slot depth.
 11. The winding arrangementof claim 8, in which a star point rail presents links extending acrossthe conductor rails and connecting coil ends.
 12. The windingarrangement of claim 10 having a star point rail, and in which the starpoint rail presents links extending across the conductor rails andconnected with coil ends.
 13. The winding arrangement of claim 1, inwhich at least two coils are connected in series, and the serialconnection is created with connections between the coils connected inseries, and in which at least some connection create sectors which areinsulated from each other.
 14. The winding arrangement of claim 1, inwhich the electric machine presents a stator with face sides and slots;the winding presents several overlapping coils comprising of the slotbars located in the slots and connector lines located at the face sidesof the stator; and the connector lines are flatter than the slot barsand the connector lines of overlapping coils are staggered and thereforelayered.